We introduce an MRI technique named CARDI, for in-vivo assessment of pulsatile fluid dynamics in the surface paravascular spaces of the pial arteries. A pair of pulsed gradient spin echo was used to detect the slow flow of CSF while suppressing the fast flow of adjacent arterial blood. Waveform of CSF over a cardiac cycle is revealed. The shape of the CSF waveforms closely resembles the pressure waveforms of the artery wall, suggesting that CSF dynamics is tightly related to artery wall mechanics. The comparison of CSF waveforms in an aging group revealed a significant age-dependency of the CSF waveforms.